Structural elements

ABSTRACT

Structural elements adapted to be connected with each other into structural units by the form-locking engagement of complementary parts constituted by apertures and projections, and formlockingly as well as force-lockingly secured in their assembled positions by locking members engaging the structural elements on several sides.

United States Patent l Oetiker [54] STRUCTURAL ELEMENTS [72] Inventor:Hans Oetiker, 2l Oberdorfstrasse,

Horgen, Switzerland [22] Filed: Oct. 30, 1969 [2l] Appl. No.; 872,702

[52] U.s. cl. 287/65, 52/645, 52/740 [5 l] lm. Cl E046 l/58, F166 5/07[58] Field 6fSearel1....52/645, 740, 726; 287/64, 65, 287/63, 55, 104

[56] References Cited UNITED STATES PATENTS 2,118,854 5/1938 Mercer..287/64 2,214,388 9/1940 summers 287/64 x 2,231,712 2/ 1941 Gleason..287/65 1451 Aug. 22, 1972 2,315,414 3/1943 Germany 287/104 2,737,2683/1956 Smith ..l5l/4l.75 X 2,863,683 l2/l958 Peterson etal. ..287/54 C2,924,31 l 2/196() Brown 287/1 89.36 A 3,22 l ,466 12/1965 Downing..52/726 Primary Examiner-Price C. Faw, Jr. Attorney-Craig, Antonelli &Hill 5 7 ABSTRACT Structural elements adapted to be connected with cachother into structural units by the form-locking` engagement ot'complementary parts constituted by apertures and projections, andform-lockingly as well as force-lockngly secured in their assembledpositions by locking members engaging the Structural elements on severalsides.

29 Claim, 35 Drawing Figures Pmmmwszzlw 3.655.863

SHEU l# 0F 4 .YINVENTOR HANS OETMER ATTORNEYS STRUCTURAL ELEMENTS Thepresent invention relates to structural elements, and more particularlyto structural elements made, for example, from sheet metal which can bereadily assembled into structural units of any type and for any purpose.

Structural elements of different types are known in the prior art whichcan be assembled into structural units of the most varied nature. Theseprior art devices utilize various connecting means for connectingtogether the individual structural elements.

For example, U. S. Pat. No. 2,737,268 (R.W. Smith) discloses structuralmembers and connecting means therefore which can be assembled intoframes, ladders and the like. However, apart from being relativelycomplicated in structure, the structural members of this patent are tiedtogether by means of bolts. As a result, the manufacture of the variousparts as well as the assembly is relatively complicated.

Additionally, interlocking connectors are known in the prior art suchas, for example, described in U. S. Pat. No. 3,221,466 for interlockingtwo beams. However, the disadvantage of such prior arty interlockingconnectors, apart from being relatively complicated resides in the factthat they do not provide for a positive locking action by the use of aseparate locking member.

Other types of connectors (U. S. Pat. No. 2,924,311 to D A. Brown) relyon the bending of tabs or the like for completion of the assembly. Thedrawbacks of such a system resides in the danger of metal fatigue due tobending, especially in case of repeated use, which may limit the usefullength of life of such device, apart from the fact that it cannot beused with plates above a certain thickness.

Other types of connector means are also known in the prior art (U. S.Pat. No. 2,863,683 to Peterson et al.) in which loop projections on onerail are extended through openings in the other rail and are held in theassembled position by a force-frictional t of keeper elements, extendingthrough the assembled loop projections. However, special precautionsmust be taken to provide the necessary force-friction tit since thistype of connection depends on this force-friction tit for its securingand therefore does not provide complete assurance against inadvertentdisengagement, for example, during thermal expansion, under theinfluence of atmospheric conditions, etc. Additionally, its use isrestricted to certain positions of the parts to avoid inadvertentdisengagement of the keeper elements.

The present invention aims at obviating the shortcomings and drawbacksencountered in the prior art and at creating structural elements, whichare simple in construction, relatively inexpensive to manufacture, easyto assemble and disassemble and safe in operation for the intendedpurposes.

The present invention essentially consists in structural elementsprovided with complementary means for mutual engagement which are lockedin their assembled position by locking means form-lockingly andforce-lockingly engaging the assembled structural elements, therebyperforming the dual function of holding the assembled elements in theirrelative position and preventing inadvertent disengagement of the parts.

According to one embodiment of the present invention, the structuralelements consist of a plurality of ladder-type elements whose webportions intermediate successive apertures are bent out for mutualengagement with one another, two assembled structural elements beingheld together in the assembled condition by a C-type locking memberfrictionally surrounding the structural elements.

According to another embodiment of the present invention, the structuralelements consist of apertured sectional members adapted to be connectedwith each other by connecting members having projections ofcomplementary configuration which are held in the assembled positions bylocking members again of approximately C-shaped cross section. Theprojecting members may be formed by appropriately dimensioned parts,spot-welded to the connector members or they may be directly punched-outof the connector members.

According to still another embodiment of the present invention,applicable in particular to heavy-gauge sectional members, eachstructural element is provided with appropriately spaced openings which,with two structural elements having their openings aligned, are held inplace by plug-type connecting members having pivotal locking meansformed thereon.

According to still further embodiments of the present invention, theconnection between two structural elements may be realized adjustably,i.e., either in predetermined tine steps by theuse of serrations orsteplessly by the use of a threaded connection.-

Accordingly to still a further embodiment of the present invention, thestructural elements may also be connected with each other in a pivotalmanner, utilizing the same principle of connection.

According to still another embodiment of the present invention, thecomplementary surfaces may be constituted by separate elements ofappropriate-configuration which are held in their assembled,form-locking condition by a force-locking sleeve member which, in tum,may be secured against inadvertent disengagement by a threadedconnection.

Accordingly, it is an object of the present invention to providestructural elements adapted to be assembled into structural units whichobviate the aforementioned shortcomings and drawbacks encountered in theprior art.

Another object of the present invention resides in structural elementsand connecting and locking means therefor which are simple inconstruction, relatively inexpensive to manufacture and easy to assembleand disassemble.

A further object of the present invention resides in structural elementswhich offer great versatility in the application thereof withoutrequiring a large number of different individual parts.

Still another object of the present invention resides in structuralelements which can be readily interlocked by simple forceandform-locking means to prevent inadvertent disengagement.

A further object of the present invention resides in structural elementswhich can be rapidly erected into sturdy, self-supporting structureswith a minimum of parts.

These and further objects, features and advantages of the presentinvention will become more obvious from the following description whentaken in connection with the accompanying drawing, which shows, for

purposes of illustration only, several embodiments in accordance withthe present invention, and wherein:

FIG. 1 is a partial elevational view of a first embodiment of aladder-type structural element in accordance with the present invention;

FIG. 2 is a cross-sectional view taken along line II-II of FIG. l;

FIG. 3 is a cross-sectional view, taken along line III- III of FIG. l;

FIG. 4 is a cross-sectional view, taken along line lV IV of FIG. 1;

FIG. 5 is an elevational view of a locking member for use in connectingtwo ladder-type structural elements of FIG. l;

FIG. 6 is a right side elevational view of the locking member of FIG. 5;

FIG. 7 isa perspective view of an angle member for connecting at anangle ladder-type structural elements of FIG. 1;

FIG. 8 is a top plan view on an assembly of laddertype elements of FIGS.1 and 7;

FIG. 9 is a cross-sectional view, taken along line IX- IX of FIG. 8;

FIG. 10 is a top plan view, similar to FIG. 8, on the assembly of amodified construction of two ladder-type structural elements inaccordance with the present inl FIG. 11 is a cross-sectional view, takenalong line K XI-XI 'of' FIG. 10;

embodiment of an apertured structural element in the form of an anglemember in accordance with the n present invention;

FIG. 14 is a perspective view on an angular connecting member forconnecting together structural elements of the type illustrated in FIG.13;

FIG. 15 is a perspective view showing two structural elements of thetype illustrated in FIG. 13 interconnected with one another by the useof an angular connector member of the type illustrated in FIG. 14 and ofC-type locking members;

FIG. 16 is a cross-sectional view, taken along line XVI- XVI of FIG. 15;FIG. 17 is elevational view of a still further modified embodiment of aconnector member in accordance with the present invention provided withprojections punched-out from the base body;

FIG. 18 is a partial perspective view of a modified assembly of the typeillustrated in FIG. 17 by means of an angular connector member wherebythe locking member and one of the elements are indicated in phantomlines;

FIG. 19 is an elevational view of a still further l modied embodiment ofan angular connector member of the type illustrated in FIG. 17;

FIG. 20 is a cross-sectional view, taken along line XX'-XX of FIG. 17;

FIG.- 21 is a perspective view illustrating a building structure made bymeans of an assembly of structural elements of the type illustrated inFIGS. l through 9 or 10 through 12;

FIG. 22 is a perspective view of a building structure made from anassembly of structural elements of the type illustrated in FIGS. 13through 16;

FIG. 23a is a perspective view of one type of hooktype suspension memberfor supporting certain parts in the assembly of FIG. 22;

FIG. 23b is a perspective view of a modified hooktype suspension memberfor supporting certain structural elements in the` assembly of FIG. 21;

FIG. 24 is a perspective view of a modified embodi- I ment of anassembly of structural elements `in accordance with the presentinvention;

FIG. 25 is an elevational view of the connector and locking means foruse in the assembly of the structural elements of FIG. 24;

FIG. 26 is a right side elevational view of the connector and lockingmeans of FIG. 25;

FIG. 27 is an exploded view of an assembly of structural elements of thetype illustrated in FIGS. 13, 14, l5 and 16, and pemlitting a finestep-wise adjustment of the relative position of the parts byA means ofa serrated connection;

FIG.v 28 is an exploded view of an assembly of structural elements ofthe type illustrated in FIGS. 13 through 16, and permitting a steplessadjustment of the relative position of the connected parts by means of athreaded connection;

FIG. 29 is an exploded view of a pivotal connection for structuralelements of the type illustrated in- FIGS. 13 through 16;

FIG. 30 is a perspective view of the assembled pivotal connection of thestructural elements illustrated in FIG. 29;

FIG. 31 is a perspective view of a modified embodiment of an assembly ofstructural elements in accordance with the present invention, utilizingseparate locking elements;

FIG. 32 is a cross-sectional view taken along line XXXII-XXXII of FIG.31;

FIG. 33 is an exploded view illustrating the assembly of the structuralelements of FIGS.'31 and 32; and

FIG. 34 is a perspective view of an assembly of structural elements,similar to FIG. 31 but utilizing dierent types of structural elements.

Referring now to the drawing wherein like reference numerals are usedthroughout the various views to designate like parts, and moreparticularly to FIGS. l through 4, a ladder-type structural elementgenerally designated by reference numeral 10 and made from suitablematerial such as band steel, is illustrated in these FIGS. which isprovided with a plurality of substantially rectangular apertures 11leaving therebetween web portions 12. If the application of thestructural elements 10 is such as not to require relatively heavy-gaugestructural elements, it may be suicient to utilize a flat, relativelythin band material that can be stored in rolls and cut to appropriatelength. To obtain the embossed configuration of the web portions l2,illustrated in FIG. 2, it is then only necessary to apply normal pincerswithin the area of the web portions l2 corresponding to the longitudinaledges 11a of the openings, to impart to the web portions 12 the raisedconfiguration illustrated in FIG. 2. In the alternative, the structuralelements or the band material from which they are cut may comePrefabricated with the embossments as illustrated in FIGS. 11 and 12 inwhich corresponding reference numerals of the series are used. Thecomplementary ladder-type structural element shown in phantom lines anddesignated by reference numeral may be made in an identical manner asstructural element 10. If so desired, its web portions 12a may be raisedin the same manner as described above. However, it is not necessary thatboth structural elements have raised web portions, and it would thus besufcient to use a flat band material for the structural element 10'provided with similar apertures l1 and flat web portions l2 as indicatedin phantom lines in FIGS. 2 and 3.

The locking members generally designated by reference numeral which maybe used for locking together structural elements of the type eithershown in FIG. 1 or in FIGS. 11 and 12 are illustrated in FIGS. 5 and 6.These locking members 20 are of substantially C-shaped and include asurface portion 21, a bottom portion 24, a top portion 25, and legportions 22 and 23. Referring to FIGS. l and 6, the dimension a of theapertures 11 in the longitudinal direction of the structural elementsmust be slightly greater than the corresponding dimension b of the webportions, whether raised or not so that the raised web portions canengage into these apertures 11. On the other hand, the height d of araised web portion (FIG. 2) should not exceed the thickness of astructural element so that the dimension c (FIG. 6) can be made at mostequal or slightly less than two times the thickness of the structuralelements 10 or 110 to provide a force-locking action against slidingmovement of the locking member, thereby precluding inadvertentdisengagement. Of course, instead of a C-shaped locking member 20, oneforming a closed rectangular profile may also be used by replacing legportions 22 and 23 with a surface portion 21.

FIG. 7 illustrates an angular connector member generally designated byreference numeral 120 whose two leg portions 120a and 120b may be at anypredetermined angle, for example, 90. Each leg portion is again providedwith a suitable number of apertures 111 and with raised web portions 112therebetween which correspond in dimensions and location to theapertures l l and web portions 12.

FIG. 8 illustrates, for exemplary purposes only, an assembly of twostraight structural elements 10a and 10b by means of one locking member20 each as well as the connection of the struc-tural element 10b withthe angular connector member 120 by means of another locking member 20whereby the angular connector member is connected on its other side atthe leg portion 120b with a further structural element 10c similar toelements 10a and 10b by means of a further locking member (not shown).It is, of course, obvious that the arrangement of FIg. 8 is equallyapplicable to the structural elements illustrated in FIGS. 10, 11 and 12or to any other type of assembly by suitably shaped connector members.Furthermore, the angular connector member 120 may be eitherprefabricated or, if relatively bendably structural elements are used,may be made from flat band material by removing one web section 12 andthen bending the band material to the desired angle after cutting thesame to the needed length.

FIGS. 10, 11 and 12 show an assembly of two structural elements 1l0a and1l0b of the type provided with prefabricated raised web portions 112corresponding to the web portions 1, 12 of FIGS. l-3. For the sake ofclarity, the locking member 20 has been omitted in FIGS. 11 and 12.

FIG. 13 illustrates structural element 210 in the form of an anglesection provided with leg portions 210a and 210b disposed, for example,at and each provided with equally spaced apertures 211, for example, ofsquare shape though any other appropriate configuration may be used,such as a rectangular configuration; the apertures 211 form in effectweb portions 212 therebetween.

FIG. 14 illustrates an angular connector member generally designated byreference numeral 220 consisting of two angularly disposed sectionsgenerally designated by reference numerals 220a and 220b, disposed toone another, for example, at right angle. Each section 220a and 220b, ineffect has two rightangle leg portions 22la, 222a and 221b, 222b,respectively, each provided with projections 223 suitably spaced tocorrespond to the spacing of apertures 211. The height of theprojections 223 is to be chosen in such a manner that it is at mostequal to but preferably slightly less than the thickness of a structuralmember. Of course, the connector member 220 may also have any othershape, for example, may be cut into two along the center line 220'.

An assembly utilizing two structuralr elements 210 connected with eachother by a connector element 220 is illustrated in FIGS. 15 and 16. Thevarious structural elements 210, of which two are shown in full lines,are each locked in their assembled position with the connector element220 by means of a locking member generally designated by referencenumeral 230 which is similar to that illustrated in FIG. 6 except thatits back portion extends in two angularly disposed planes correspondingto the planes of the leg portions 210a and 210b. The locking element 230is therefore of a shape similar to locking member 20 of FIGS. 5 and 6with the back portion thereof subdivided into two sections disposed atright angle to one another so that two Ls result each having a long legportion 231 and 231', a shorter leg portion 232 and 232' and atransverse connecting web portion 233 and 233' connecting the legportions 231 and 232 and the leg portions 231' and 232', respectively.Again, the dimensions e of the connecting web portions 233 should be atmost equal to or just slightly smaller than the combined thickness ofone structural element 210 and of a section element 220a and 220b so asto assure a frictional or force-locking engagement. The assembly ofFIGS. 15 and 16 may be further used to connect additional structuralparts 210, shown in phantom line to the connector member 220.Additionally, a flat structural element 210' having, for example, tworaised portions 223' in place of two apertures 211 may be assembled bylocking member 230 to structural element 210, as shown in phantom linesin FIG. 16.

FIGS. 17, 18, 19, and 20 illustrate a still further modified embodimentof various structural elements and connector members in accordance withthe present invention in which a structural element generally designatedby reference numeral 310 is provided with rectangular apertures 3l 1.Instead of projections which are spot-welded to the base body of theconnector members 220 of FIGS. 14 and l5, the connector elementsgenerally designated by reference numerals 230a (FIG. 17), 320b (FIG.18), or 320c(FIG. 19) are provided with claw-like projecting protions323 suitably punched out by a special punching tool in such a mannerthat the four comers 324 of a rectangle are punched out in the formresembling a flattened S while intermediate flat portions 325 remain inthe base body. The configuration of the punched-out comers isillustrated in detail in cross section in FIG. 20. A suitable lockingmember 330 is indicated in phantom line in FIG. 18 which is similar tolocking member 20.

FIG. 21 illustrates a simple assembled structure for a mobile home orthe like made from various structural elements and connector members ofthe type illustrated in FIGs. 1 through 12 suitably interlocked bylocking members. As can be seen, the present invention offers greatversatility by rthe use of simple structural elements which areconnected with each other by the inter-engagement as described above,locked in position by a locking member that is merely slipped over theassembled structural elements to hold the same assembled form-lockinglywhile being itself forcelockingly secured by frictional engagement.

Since the locking member is of substantially C- shaped configuration(FIGS. and 6) or of double-L- shaped configuration (FIG. 16), it willhold in any assembled position due to the frictional engagement of theleg portions thereof which possess an inherent limited flexibility sothat the danger of becoming loose in certain position, due togravitational forces and, for example, as a result of vibrations,stresses, loads, etc. is minimized.

FIG. 22 is a perspective view, illustrating a simple structural unitmade from the structural elements and connector members of FIGS. 13through 16. In this embodiment parts such as, cots, shelves, etc. can besuspended from the structural elements byhook-like members generallydesignated by reference numeral 400 and illustrated in greater detail inFIG. 23a while shelt'mg, flooring, etc. can be supported on hookshapedsupport members generally designated by reference numeral 500 and morefully illustrated in perspective view in FIG. 23b. Of course, similar,or other types of support members, adapted to be hooked into aperturesof the structural elements, may be used in conjunction with thisembodiment as well as the embodiment of FIG. 2l to support beds,flooring, ceiling, CtC.

The structures of FIGS. 21 and 22 are merely illustrative of variousassemblies possible with the structural elements of the presentinvention which may be used for similar purposes as mobile homes, armytents, emergency shelters, and the like. The structures can be covered,for example, by suitably fabric, provided, for instance, with windowsand door openings formed by zippers. However, the assembled structuresmay also be covered by woodenypanels, synthetic resinous panels, orpanels made from any other known material or cornbination of materialsas may be appropriate. As is obvious, the various shapes and forms ofthe final assembly can be varied at will be the use of differentconnector elements, FIGS. 2l and 22 being nearly representative of thegeneral type of structure feasible with the present invention.Furthermore, assemblies of the type similar to FIGS. 21 and 22 may alsobe realized by the use of structural elements described more fullyhereinafter by reference to FIGS. 24 through 34.

FIG. 24 illustrates a simple assembly of a right angle structuralelement generally designated by reference numeral 600 with, for example,a straight structural element generally designated by reference numeral600'. Each of the structural elements 600 and 600 is provided withsuitable apertures 610 so arranged and spaced as to permit alignmentthereof in the assembled condition of the structural elements. Plug-typeconnecting and locking members generally designated by reference numeral620 are inserted with the shank portion 621 thereof through alignedapertures 610 so that the head portions 622 rest against the outersurface of the structural element 600'. To lock a member 620 in positioneach member 620 is provided with a longitudinal axial slot 623 cut infrom the end opposite the head portion 22, in which is pivotally mountedby means of a pivot pin 624 extending at right angle to the axial shankportion 621, a locking element 625 that is,

of substantially rectangular configuration with a rounded-off endsection 625' and has an elongated aperture 626 corresponding in itswidth (narrower dimension) approximately to the pin diameter. Afterinsertion of the shank portion 621 with aligned locking member 625through the aligned openings 610 as illustrated in full lines in FIGS.25 and 26, the locking member 625 is rotated through 90-a in thedirection of the arrow A and is then longitudinally displaced at rightangle to the axis of the shank portion 621 in the direction of arrow Buntil pin 624 is about in the center of aperture 626 as indicated indash and dot lines. The dimension g is thereby so selected that the topedge 625' of locking member 625 is held frictionally against the bottomsurface of the next adjacent structural element, i.e. g s 2h, where h isthe thickness of a structural element 600 or 600 (FIG. 24).

FIG. 27 illustrates a connection generally designated by referencenumeral 700 providing a ne, step-wise adjustment of the relativeposition of the structural elements 210 to be connected with each other.For this purpose, a flat connector member 710 is provided which includessubstantially rectangular projections 711 at one face thereof,corresponding to the projections 233 of FIG. 14. The projections 711 maybe suitably secured to the connector member 810, for example, byspot-welding or may be formed integrally therewith. Additionally, theconnector member 710 is provided with an elongated aperture 712extending over a length substantially greater than the spacing betweentwo apertures 211 and being provided with fine-tooth serrations 713along both long sides of the aperture 712. An insert member generallydesignated by reference numeral 715 is provided with a base portion 716having tine-tooth serrations 717 on both sides thereof of complementaryshape to the serrations 713 so that the insert member 715 can beinserted ina form-locking manner into the opening 712 at any desiredplace. The insert member 715 is additionally provided with projections718 of identical conguration to the projections 711. To provide anassembly by means of this type of connector member, it is only necessaryto insert the insert member 715 in proper pre-selected position into theaperture 712, thereafter place the structural element 210 with itsapertures 211 in alignment with the projections 718 and thereupon lockthe thus-assembled parts by means of a C-shaped locking member 730 ofsimilar construction to thatillustrated in FIGS. and 6. The connectorelement 710 is connected by means of its projections 711 with anotherstructural element (not shown) similar to the structural element 210 inthe manner described in connection with FIGS. 13 through 16. It isobvious that the two structural elements 210 can thus be assembled bythe double-connector member 710 in predetermined spaced relationship toone another since the .insert member 715 can be inserted with itsserrations 717 at any desired place, thereby permitting a ne, yetprecise adjustment of the relative position of these members. This isimportant, for example, in those cases where the standard length may notfit due to the particular location and/or installation of the structuralelements, as for example, for purposes of angular trussing or bracing,schematically illustrated in FIG. 22.

FIG. 28 illustrates an infinitely adjustably assembly of two structuralelements 210 each provided with suitable apertures 211 by means of aconnector assembly generally designated by reference numeral 800 whichincludes two symmetrical, right-angle members generally designated byreference numerals 810 and 810', of which a respective leg portion 811and 811 is provided with two projections 812 each of complementary shapeto the apertures 211. The other leg portions 813 and 813' of anglemembers 810 and 810 are each provided with a bore 814 and 814',respectively, whereby bore 814 is a plain bore of slightly largerdiameter than the screw 815 while the bore 814' is provided with intemalthreads adapted to engage with the external threads of the screw 815.Each angle member 810 is secured to its corresponding structural element210 by means of a C-shaped locking member generally designated byreference numeral 830 of similar shape to the locking member 730illustrated in FIG. 27. For purposes of assembly, for example, at rst alocking member 830 is threaded over the free end of a structural element210 in the direction of arrow C beyond the first two apertures 211.Thereupon, the projections 812 of the angle member 810' are assembled toengage the corresponding apertures 211 whereafter the locking member 830is retracted in the direction of arrow D until it assumes the positionillustrated in FIG. 28 in which it holds the parts 810 and 210 informlocking and force-locking engagement. The angle member 810 isassembled to the other structural element 210 in a similar manner.Thereafter, the screw 815 is inserted through the Unthreaded bore 814and is engaged in the threaded bore 814 whereby the relative position ofthe two structural elements 210 can be adjusted steplessly by adjustmentof screw 815. Such infinitely adjustable connection is of importance,inter alia, when the structural elements are used as trusses or bracesas schematically indicated in FIG. 22, and in particular where suchtrusses or braces are under tensional stresses.

Flg. 29 illustrates a pivotal connection of two structural elements 210each provided again with apertures 211. The pivotal connection generallydesignated by reference numeral 900 includes a rst connector member 910constituted by a relatively short, flat structural element provided withtwo projections 911 or such shape and configuration as to becomplementary to apertures 211 and is provided with a bore 912. A

second connector member generally designated by reference numeral 915and formed again by a relatively short, flat structural element isprovided with two apertures 916 of shape and spacing similar toapertures 21 l and complementary to projections 911. Additionally, theconnector member 915 is provided with a bore 917 which is located inprecisely the same place, in relation to the apertures 916 as the bore912 is located in relation to the projections 911. A pivot membergenerally designated by reference numeral 920 consists of asubstantially rectangular body part 921 of a shape and dimensioncomplementary to apertures 211 from which project pin members 922 and923 in the upward and downward directions for engagement into bores 917and 912, respectively. The structural elements 210 as well as theconnector elements 910 and 915 are of the same thickness. The part 921has a thickness equal to or slightly less than the thickness of astructural element 210, while projections 911 have a thickness equal toor slightly less than two times the thickness of a structural element210, 915. During assembly, apertures 211 of the left structural member210 as viewed in FIG. 29 are brought into engagement with projections911, pin 923 is thereupon inserted into bore 912, j

aperture 211 of the right structural element is thereupon engaged withthe part 921 of the pivot member 920 and thereafter connector member 915is assembled in such a manner that pin 922 engages in its bore 917 whileapertures 916 receive projections 911. A locking member 930 ofsubstantially similar shape as locking members 20, 730 and 830 though ofsomewhat greater length is thereupon moved from its position indicatedin FIG. 29 into the position indicated in FIG. 30 in which position thetwo structural elements are pivotally connected with each other. Thepivot member 920 is held in its assembled condition within bores 912 and917 by reason of the fact that the right end section of connectormembers 910 and 915, as viewed in FIGS. 29 and 30, cannot becomedisengaged from pins 922 and 923 due to the locking effect of lockingmember 930 which precludes the structural elements from any substantialbending in a direction away from the pivot member 920. Since thestructural elements 210 as well as the part 921 are of the samethickness, a safe pivotal connection is established which is reliable inoperation and able to withstand relatively high stresses.

FIGS. 31, 32 and 33 show an assembly of structural elements generallydesignated by reference numeral 950, similar to structural elements 210but provided with circular gspaced apertures 951, by means of connectormembers 960 of circular shape, complementary to apertures 951 and of athickness equal to or slightly less than twice the thickness of astructural element 950, and by means of a locking member generallydesignated by reference numeral 970 which with its top 971, its bottom972 and its sides 973 and 974 forms a sleeve of substantiallyrectangular cross section slightly greater than the width of a connectormember 950 and slightly higher than twice the thickness of a connectormember 950.

The locking member 970 is additionally provided in its top and bottomsurfaces 971 and 972 with aligned bores 975 and 975' for insertion of ascrew generally designated by reference numeral 976 held in position bya nut 977 as will be described more fully hereinafter.

l l Additionally, the top surface 971-is provided with a semi-circularlyshaped recess 971' to facilitate assembly as will be described morefully hereinafter.

For purposes of assembly, the locking member 970 is threaded over theupper structural element 950 as viewed in FIG. 33 until its left endlays bare at least three apertures 951. The bottom structural element950 is thereupon brought into alignment so that three apertures of thetop structural element 950 are in alignment with three apertures 951 ofthe bottom structural element. The locking member 970 is thereupondisplaced in the direction of arrow E until its recess 971' assumes theposition indicated in phantom line-in FIG. 33. Depending on theconguration of the recess 971 the unrecessed bottom surface 972 coversat least twothirds or three-quarters of the corresponding aperture 951of the bottom structural element 950 as measured in the diarnetricdimension thereof. Obviously, by giving the recess 971' the desiredconfiguration, i.e., by making the same more or less deep, the extent ofcoverage by the bottom surface of the corresponding aperture cari bevaried. A connector element 960 can then be safely inserted into thethird aperture from the end of the top structural element 950 since itis prevented from falling through the corresponding aligned bottomapertures 951 by the bottom surface 972 of the locking member 970.Thereupon, the locking member 970 is displaced further in the directionof arrow E until its recess 970' assumes the position indicated by thedash lines. The other connector member 960 may then be safely insertedinto the left end aperture of the top structural element 950 since it isalso prevented from falling through the aligned corresponding bottomaperture 951 by the bottom surface 972. Thereafter, the locking member970 is further displaced in the direction of arrow E until its bores 975and 975' are in alignment with aligned, empty apertures of thestructuralk element in FIG. 33. The screw 976 and bolt 977 canthereafter be readily assembled as shown in FIG. 32 whereby the lockingmember970 is securely held against any inadvertent displacementnotwithstanding its frictional contact with the structural elements.

FIG. 34 illustrates an assembly of structural elements 210 withapertures 211 similar to the assembly illustrated in FIGS. 31 through 33with the dilerence that the apertures 211 in the structural elements areof rectangular cross section so that the connector members 960' are ofsimilar rectangular complementary shape.

The connection of structural elements illustrated in FIGS. 31 through 34is simple, requires relatively few, inexpensive parts, which can bereadily manufactured, and is easy to assemble since the locking member970 itself can be utilized for that purpose, thanks to its recessedportion 971'. Additionally, the screw and nut connection 976, 977assures against any inadvertent sliding movement of the locking member970 which might jeopardize the safe connection of the structuralelements. Of course, instead of a screw and nut connection, any othersuitable type of locking connection may be used, such as a lock nut,cotter pin or the like.

While I have shown and described several embodiments in accordance withthe present invention, it is understood that the same is not limitedthereto but it susceptible of numerous changes and modifications asknown to a person skilled in the art. For example, the configuration ofthe apertures may be varied at will provided the projections or raisedweb portions are similarly modified. The connectormembers may also haveany desired configuration and any angular relationship and may includetwo, three, four or more leg portions as needed for a particularapplication. Likewise, the thickness or strength of the material can bevaried at will depending on the intended purposes in a givenapplication. In connection with. Prefabricated houses, heavier gaugematerial is needed than, for example, with structural assemblies forsmaller units. The siding to be used with structural units in theirassembled condition may also be varied at will. For example,

for military purposes, canvas or other fabrics could be used whereasappropriate siding and roofing paneling,

e.g. made from wood, particle boards, synthetic resinous materials,etc., may be used in other applications.

' Additionally, the various parts including structural elements may bemade of any suitable synthetic. resinous material, thereby facilitatingmanufacture since such parts can be readily made by injection molding orthe like. Such synthetic resinous materials may be used in particularwith the present invention when used in smaller structures. Moreover,the present invention is not limited to any particular size ofstructures but may be used even with relatively small size parts, I

e. g., as educational toys for children, in whichcase, the use ofsynthetic resinous materials is particularly appropriate. V

Consequently, I do not wish to be limited to the details shown anddescribed herein but intend to cover all such changes and modificationsas are within the scope of those skilled in the art. v

I claim:

l. Structural elements formed by parts having substantially oppositeflat surfaces, of which the flat surface of one part is provided withsubstantially -identical apertures, and adapted to be assembledintostructural units, characterized in that connector means are provided onthe structural parts for form-lockingly connecting together twostructural elements, the connector means fomiing in effect at least onemale part on one structural part engaging in a complementary apertureextending through the other structural part to form-lockingly connectwith one another two structural elements, the height of the male partbeing at most substantially equal to the thickness of the otherstructural part so that the overall thickness of the two interlockedparts is equal overall to the thickness of the two structural parts andthe surfaces thereof opposite their abutting surfaces are substantiallyflat and devoid of any projections in a direction away from therespectively opposite part, and locking means at least partlysurrounding and engaging the thus form-locking assembled structuralelements on the two opposite flat surfaces thereof to form-lockingly aswell as forcelockingly hold said assembled structural elements in theirassembled conditions, said locking means being provided exclusively withflat surfaces engaging with the opposite flat surfaces of the structuralparts to enable sliding assembly and disassembly 2. Structural elementsaccording to claim 1, characterized in that said means means is ofapproximately C- shape.

3. Structural elements according to claim l, characterized in that saidlocking means is of approximately double-L-shape with the two Lsdisposed at an angle to each other corresponding to the angle formed byleg portions of an angular member constituting one of said structuralelements.

4. Structural elements according to claim 1, characterized in that saidlocking means has such a cross-sectional protile as to engage theassembled structural elements at least in part on all exposed surfacesthereof.

5. Structural elements according to claim 4, characterized in that thestructural elements are apertured, leaving therebetween web portionsconstituting the male parts of said connector means.

6. Structural elements according to claim 5, characterized in that thestructural elements are constituted of regularly apertured band materialwith at least some web portions between adjacent apertures raised toform said male parts.

7. Structural elements according to claim 5, wherein said structuralelements are relatively flat in transverse cross section with only someweb portions raised.

8. Structural elements according to claim 5, wherein all web portionsare raised to form male parts.

9. Structural elements according to claim 4, characterized in thatconnector means forming male parts are formed integrally with astructural element.

10. Structural elements according to claim 9, characterized in that themale parts are formed by claw-like projections punched out from thecorresponding structural element.

1 1. Structural elements according to claim 9, c haracterized in thatthe structural element including the connector means forms an angularsection with at least two angularly disposed parts.

l2. Structural elements according to claim ll, characterized in that thestructural element with the connector means has several angularlydisposed parts each provided with male parts.

13. Structural elements according to claim 9, characterized in that thestructural elements with the connector means has several angularlydisposed parts each provided with male parts.

14. Structural elements according to claim 13, wherein said male partsare spot-welded to a structural element.

15. Structural elements according to claim 1, characterized in that eachstructural element is apertured leaving therebetween web portionsconstituting in ef-l fect said male parts.

16. Structural elements according to claim l5, wherein all web portionsare raised to form male parts.

17. Structural elements according to claim 1 characterized in thatconnector means forming male parts are formed integrally with astructural element.

18. Structural elements according to claim 17, characterized in that thestructural element with the connector means forms an angular sectionwith at least two angularly disposed parts.

19. Structural elements according to claim l, characterized in that saidconnector means is a separate connector member including at least onemale part and provided with a toothed aperture means,'insert meansprovided with complementary toothed surface portions for engagement inthe toothed aperture means in any predetermined position and having atleast one male part, the two last-mentioned male parts being adapted tobe inserted into complementary apertures of the structural elementswhile said locking means holds the thus-assembled parts form-lockinglyand forcelockingly in their respective positions.

20. Structural elements according to claim 1, characterized in that saidconnector means includes two symmetrical angle members, each provided onone leg portion with at least one male part adapted to engage into thecorresponding aperture of a respective structural element, the other legportion of one of the angle members being provided with an unthreadedbore while the leg portion of the other angle member is provided with athreaded bore, and a threaded connecting means extending through theunthreaded bore and engaging with the threads of the other bore, eachangular member being forrn-lockingly and force-lockingly held in theassembled position with its corresponding structural element by arespective locking means.

21. Structural elements according to claim l, characterized in that saidconnector means provides a pivotal connection between two aperturedstructural elements and includes a rst connector member withcomplementary male parts and a tirst bore, a second connector memberprovided with apertures corresponding to the apertures in a structuralelement and with a bore located in substantial alignment to thefirst-mentioned bore with the male parts of the rst connector memberengaging in the apertures of one of the structural parts and said secondconnector member disposed on the opposite side of said one structuralpart, and pivot means having a body portion complementary to an aperturein a structural element and pin portions adapted to engage into thebores, the other structural element being in engagement with said bodypart and being pivotally held between the two connector members.

22. Structural elements according to claim 2l, characterized in that themale parts on said first connector member have about the thickness oftwo structural elements whereas the thickness of said body portioncorresponds to the thickness of a structural element.

23. Structural elements according to claim 1, characterized in that saidconnector means are separate connector elements of a shape complementaryto the apertures in the structural elements, and in that said lockingmeans surrounds the aligned structural elements on all sides thereof andis provided in one major surface with a recessed portion to enableassembly.

24. Structural elements according to claim 23, characterized in thatsaid locking means is provided with aligned apertures within the centerportion thereof, the connector members being inserted into alignedapertures of the structural elements, leaving therebetween one set ofaligned empty apertures, and securing means extending through thealigned apertures of the locking means and the aligned apertures, leftfree, of the structural members, to hold the locking means in place.

25. A structural assembly comprising two structural flat parts ofsubstantially identical thickness, at least one of said two structuralparts being provided with a plurality of regularly spaced apertures ofpredetermined conflguration extending through said one structural part,at least the other of said two structural parts being provided with aplurality of similarly regularly spaced male projections of a shapecomplementary to said predetermined shape and of a height at most equalto the thickness of a structural part, the opposite surface of saidother structural part being substantially planar except of saidprojections and the two structural parts in their assembled condition,when the projections engage in corresponding apertures, being disposedcompletely between two parallel planes spaced apart a distance ofsubstantially twice the thickness of a structural part and extendingthrough the relatively flat outer surfaces of each structural part,readily detachable locking means slidingly engaging over the thusassembled, flat outer surface of the two structural parts toform-lockingly as well as forcelockingly hold together said assembledstructural parts, said locking means including substantially flatopposite engaging surfaces spaced apart a distance of about thethickness of the two assembled structural parts and engaging with saidouter surfaces of the stnictural parts.

26. The combination according to claim 25, wherein said locking means isof approximately C-shaped con-y figuration in cross section.

27. The combination according to claim 25, wherein said structural partsare of flat band steel, each with regularly spaced apertures.

28. The combination according to claim 27, wherein said band steel partsform web portions between said regularly spaced apertures with some ofsaid web portions bent out -of the plane of the respective flat bandsteel.

29. The combination according to claim 25, wherein i both structuralparts essentially consist of relatively 1 thin and bendable ladder-type,flat band steel material having regularly spaced apertures forming webportions therebetween which are adapted to bend outA to form saidprojections. p

1. Structural elements formed by parts having substantially oppositeflat surfaces, of which the flat surface of one part is provided withsubstantially identical apertures, and adapted to be assembled intostructural units, characterized in that connector means are proVided onthe structural parts for formlockingly connecting together twostructural elements, the connector means forming in effect at least onemale part on one structural part engaging in a complementary apertureextending through the other structural part to form-lockingly connectwith one another two structural elements, the height of the male partbeing at most substantially equal to the thickness of the otherstructural part so that the overall thickness of the two interlockedparts is equal overall to the thickness of the two structural parts andthe surfaces thereof opposite their abutting surfaces are substantiallyflat and devoid of any projections in a direction away from therespectively opposite part, and locking means at least partlysurrounding and engaging the thus formlockingly assembled structuralelements on the two opposite flat surfaces thereof to form-lockingly aswell as force-lockingly hold said assembled structural elements in theirassembled conditions, said locking means being provided exclusively withflat surfaces engaging with the opposite flat surfaces of the structuralparts to enable sliding assembly and disassembly.
 2. Structural elementsaccording to claim 1, characterized in that said means means is ofapproximately C-shape.
 3. Structural elements according to claim 1,characterized in that said locking means is of approximatelydouble-L-shape with the two L''s disposed at an angle to each othercorresponding to the angle formed by leg portions of an angular memberconstituting one of said structural elements.
 4. Structural elementsaccording to claim 1, characterized in that said locking means has sucha cross-sectional profile as to engage the assembled structural elementsat least in part on all exposed surfaces thereof.
 5. Structural elementsaccording to claim 4, characterized in that the structural elements areapertured, leaving therebetween web portions constituting the male partsof said connector means.
 6. Structural elements according to claim 5,characterized in that the structural elements are constituted ofregularly apertured band material with at least some web portionsbetween adjacent apertures raised to form said male parts.
 7. Structuralelements according to claim 5, wherein said structural elements arerelatively flat in transverse cross section with only some web portionsraised.
 8. Structural elements according to claim 5, wherein all webportions are raised to form male parts.
 9. Structural elements accordingto claim 4, characterized in that connector means forming male parts areformed integrally with a structural element.
 10. Structural elementsaccording to claim 9, characterized in that the male parts are formed byclaw-like projections punched out from the corresponding structuralelement.
 11. Structural elements according to claim 9, characterized inthat the structural element including the connector means forms anangular section with at least two angularly disposed parts. 12.Structural elements according to claim 11, characterized in that thestructural element with the connector means has several angularlydisposed parts each provided with male parts.
 13. Structural elementsaccording to claim 9, characterized in that the structural element withthe connector means has several angularly disposed parts each providedwith male parts.
 14. Structural elements according to claim 13, whereinsaid male parts are spot-welded to a structural element.
 15. Structuralelements according to claim 1, characterized in that each structuralelement is apertured leaving therebetween web portions constituting ineffect said male parts.
 16. Structural elements according to claim 15,wherein all web portions are raised to form male parts.
 17. Structuralelements according to claim 1, characterized in that connector meansforming male parts are formed integrally with a structural element. 18.Structural elements according to claim 17, characterized in that thestructUral element with the connector means forms an angular sectionwith at least two angularly disposed parts.
 19. Structural elementsaccording to claim 1, characterized in that said connector means is aseparate connector member including at least one male part and providedwith a toothed aperture means, insert means provided with complementarytoothed surface portions for engagement in the toothed aperture means inany predetermined position and having at least one male part, the twolast-mentioned male parts being adapted to be inserted intocomplementary apertures of the structural elements while said lockingmeans holds the thus-assembled parts form-lockingly and force-lockinglyin their respective positions.
 20. Structural elements according toclaim 1, characterized in that said connector means includes twosymmetrical angle members, each provided on one leg portion with atleast one male part adapted to engage into the corresponding aperture ofa respective structural element, the other leg portion of one of theangle members being provided with an unthreaded bore while the legportion of the other angle member is provided with a threaded bore, anda threaded connecting means extending through the unthreaded bore andengaging with the threads of the other bore, each angular member beingform-lockingly and force-lockingly held in the assembled position withits corresponding structural element by a respective locking means. 21.Structural elements according to claim 1, characterized in that saidconnector means provides a pivotal connection between two aperturedstructural elements and includes a first connector member withcomplementary male parts and a first bore, a second connector memberprovided with apertures corresponding to the apertures in a structuralelement and with a bore located in substantial alignment to thefirst-mentioned bore with the male parts of the first connector memberengaging in the apertures of one of the structural parts and said secondconnector member disposed on the opposite side of said one structuralpart, and pivot means having a body portion complementary to an aperturein a structural element and pin portions adapted to engage into thebores, the other structural element being in engagement with said bodypart and being pivotally held between the two connector members. 22.Structural elements according to claim 21, characterized in that themale parts on said first connector member have about the thickness oftwo structural elements whereas the thickness of said body portioncorresponds to the thickness of a structural element.
 23. Structuralelements according to claim 1, characterized in that said connectormeans are separate connector elements of a shape complementary to theapertures in the structural elements, and in that said locking meanssurrounds the aligned structural elements on all sides thereof and isprovided in one major surface with a recessed portion to enableassembly.
 24. Structural elements according to claim 23, characterizedin that said locking means is provided with aligned apertures within thecenter portion thereof, the connector members being inserted intoaligned apertures of the structural elements, leaving therebetween oneset of aligned empty apertures, and securing means extending through thealigned apertures of the locking means and the aligned apertures, leftfree, of the structural members, to hold the locking means in place. 25.A structural assembly comprising two structural flat parts ofsubstantially identical thickness, at least one of said two structuralparts being provided with a plurality of regularly spaced apertures ofpredetermined configuration extending through said one structural part,at least the other of said two structural parts being provided with aplurality of similarly regularly spaced male projections of a shapecomplementary to said predetermined shape and of a height at most equalto the thickness of a structural part, the opposite surface of saidother structural part being substantially planar except of saidprojections and the two structural parts in their assembled condition,when the projections engage in corresponding apertures, being disposedcompletely between two parallel planes spaced apart a distance ofsubstantially twice the thickness of a structural part and extendingthrough the relatively flat outer surfaces of each structural part,readily detachable locking means slidingly engaging over the thusassembled, flat outer surface of the two structural parts toform-lockingly as well as force-lockingly hold together said assembledstructural parts, said locking means including substantially flatopposite engaging surfaces spaced apart a distance of about thethickness of the two assembled structural parts and engaging with saidouter surfaces of the structural parts.
 26. The combination according toclaim 25, wherein said locking means is of approximately C-shapedconfiguration in cross section.
 27. The combination according to claim25, wherein said structural parts are of flat band steel, each withregularly spaced apertures.
 28. The combination according to claim 27,wherein said band steel parts form web portions between said regularlyspaced apertures with some of said web portions bent out of the plane ofthe respective flat band steel.
 29. The combination according to claim25, wherein both structural parts essentially consist of relatively thinand bendable ladder-type, flat band steel material having regularlyspaced apertures forming web portions therebetween which are adapted tobend out to form said projections.